Addition agent and process for producing magnesium-containing cast iron



United States Patent ADDITION AGENT AND PROCESS FOR PRODUC- INGMAGNESHJlVl-CONTAINTNG CAST IRON No Drawing. Application January 23,1953, Serial No. 332,998

14 Claims. (Cl. 75-130) The present invention relates tomagnesium-containing addition agents for the treatment of molten castiron and to a process for treating molten cast iron with said additionagents to incorporate magnesium in said cast iron and to produce castiron having graphite in a compacted form, particularly a spheroidalform.

It is well known that magnesium is highly reactive in the presence ofmolten cast iron. It was disclosed in the Millis, Gagneb-in & Pilling U.S. Patent No. 2,485,760 that cast irons containing small but effectiveamounts of magnesium possessed remarkable new properties and werecharacterized by graphite in a spheroidal form. In the aforementionedpatent, it was pointed out that it is possible to add metallic magnesiumper se to molten cast iron when the latter is in a cold viscous orsemifluid state. However, it was pointed out in said patent that for thepurpose of operating in a commercial foundry it was usually preferableto introduce magnesium into molten cast iron in the form of an alloy ofmagnesium with a metal such as nickel and/ or silicon and/ or copperwith or without other elements such as iron, manganese, etc.Satisfactory alloys to be used for the purpose of incorporatingmagnesium into cast iron are described in U. S. Patents Nos. 2,485,760,2,529,346, 2,563,859, etc. It has been found that agents and alloys madeof ferrosilicon and magnesium and substantially devoid of strategicmetals, such as copper, nickel, etc., offer promising advantages to thecommercial foundrymen because of the low cost and the absence ofstrategic elements. However, it has been found that whenferrosiliconmagnesium alloys are employed in a commercial foundry forthe purpose of introducing magnesium into molten cast iron, these alloysdo not have the desired lo-w reactivity, do not produce the desired highmagnesium re covery, and have other practical disadvantages.

The foundry art has been faced with the problem of providing an additionagent to be used for incorporating magnesium into 'cast iron which wouldhave satisfactory addition characteristics when added to molten castiron, which would provide satisfactory recovery of retained magnesium inthe molten cast iron treated therewith, which would not require anysubstantial amounts of strategic elements and which could be employedunder commercial foundry conditions for the production ofmagnesium-containing cast iron.

Although attempts have been made to overcome the foregoing difficultiesencountered in the commercial foundry none, as far as We are aware, wasentirely successful when carried into practice commercially on anindustrial scale.

It has now been discovered that by the inclusion of a special ingredientand by critically proportioning all ingredients an agent comprisedlargely of silicon and magnesium will perform satisfactorily in thecommercial foundry for the purpose of introducing magnesium into moltencast iron.

2,762,705 Patented Sept. 11, 1956 It is an object of the presentinvention to provide an addition agent comprised largely of silicon andmagnesium, and having the property on a commercial scale ofsatisfactorily incorporating magnesium into molten cast iron.

Another object of the invention is to provide an addition agent fortreating molten cast iron having a special ,and critical content ofingredients and a critical proportioning of said ingredients.

Another object of the invention is to provide a magnesium containingaddition agent having an enhanced simultaneous inoculating effect whenadded to molten cast lI'OIl.

The invention also contemplates providing a process for producingmagnesium-containing cast iron by means of a specialmagnesium-containing agent having a special proportioning of ingredientswhich cooperate with molten cast iron baths to introduce magnesium morequietly and more efficiently into said baths.

Itis a further object of the invention to provide a magnesium-containingaddition agent satisfactory in a commercial foundry for the purpose ofintroducing mag- .nesium into molten cast iron but which issubstantially devoid of strategic heavy metals.

Other objects and advantages will become apparent from the followingdescription.

Generally speaking, the present invention contemplates an addition agentor alloy adapted for the treatment of ,molten cast iron baths andcomprising about 10% to about 25% magnesium, about 3% to about 14%calcium, ,up to about 30% iron and the balance essentially silicon ,withthe ratio of magnesium to calcium being between about 13:1 and about 5.5:l. The invention also contemplates the treatment of mo ten cast ironwith said agents to incorporate and retain magnesium in said molten castiron.

Magnesium-containing agents within the invention represent practicalcompositions useful for the purpose of introducing magnesium into castiron and perform this function satisfactorily in spite of the fact thatno content of heavy, strategic metal such as copper, nickel, etc., isrequired. The accomplishment of this result is believed due to thecooperative effect of the ingredients specified in the agents definedhereinbefore, which effect is obtained when said agents are introducedinto molten cast iron. Thus, when the magnesium content exceeds about30%, the increased flare, heat and smolce resulting from the addition ofthe agent to molten iron make the agent objectionable from a practicalviewpoint. When the magnesium content is decreased below about 10%, theefliciency at which magnesium is introduced into molten iron isundesirably decreased. The calcium content of the agent, in conjunctionwith the magnesium content, is likewise critical and the calcium contentof the agent as above this level of cell-' should not exceed about 14%cium, the efiiciency at which magnesium is introduced into molten ironis again undesirably decreased and other practical difliculties areencountered, including excessive slag formation, etc. On the other hand,the calcium content should not be lower than about 3% "as otherwise itis not possible to obtain the new results contemplated by the presentinvention, including more rapid, quieter solution of the agent in moltencast iron with higher recovery of magnesium in the cast iron. The ironcontent of the agents contemplated in accordance with the presentinvention should not substantially exceed about 30%, since theefliciency of the magnesium introduction into molten cast iron from saidagents is undesirably decreased at higher iron levels and otherdifliculties are encountered. For example, the manufacture of alloyshaving higher iron contents is attended by increasingly violentreactions. The balance of the agents and alloys contemplated by theinvention is essentially silicon, including minor amounts of impuritiesand ingredients which do not change the basic and novel characteristicsof the composition. The silicon content of the agents is about 45% toabout 75% to cooperate with the other constituents of the agents,notably magnesium and calcium, to more efficiently introduce magnesiumcontained in said agents into molten iron when said agents are addedthereto.

It is very important that the agents contemplated by the presentinvention contain magnesium and calcium in the ratios set forth herein.When these ratios of magnesium and calcium are maintained, greatlyimproved results are obtained upon adding the agents to molten castiron, including more rapid, quieter and smoother addition of the agentand higher recovery of magnesium in the cast iron.

The present invention also contemplates the treatment of molten castiron baths with the agents provided by the invention for the purpose ofintroducing magnesium in small but effective amounts into said baths. Ithas been found that a cooperative effect takes place between the agentscontemplated by the invention and molten cast iron baths which providesin the molten baths a higher recovery of magnesium contained in saidagents. This effect is associated with the present process for treatingmolten cast iron employing the aforedescribed agents and is notencountered when agents having compositions outside the ranges ofingredients set forth hereinbefore are employed in treating molten castiron in accordance with the process contemplated by the presentinvention.

The agents contemplated by the present invention preferably containabout 12% to about 20% magnesium, about to about calcium, about 8% toabout iron, with the balance essentially silicon, and have a ratiobetween the magnesium and calcium contents of the agents within thelimits of about 1.5:1 and about 3.511. It is further preferred that theratio between the magnesium and silicon contents of the agent bemaintained between about 1:3 and about 1:6. These preferred agentsenable maximum recovery of contained magnesium when added to molten castiron. In addition, when such agents are employed in the production ofgray or graphitic cast iron, consistent production of spheroidalgraphite structures and of high mechanical properties are achieved.Furthermore, preferred addition characteristics are obtained.

The agents contemplated by the present invention and falling within theranges set forth herein advantageously can contain small amounts ofcerium, e. g., about 0.25% to about 5% cerium, preferably about 0.5% toabout 2% cerium, and these small mounts of cerium contribute to quietaddition behavior of the agents and promote recovery of magnesium inmolten cast iron treated therewith.

Besides the essential ingredients magnesium, calcium, iron and silicon,the agents also may contain small amounts of incidental impurities,including phosphorus, etc, introduced from the raw materials employed inproducing the agents, etc. In addition to impurities, the alloy may alsocontain up to about 1% nickel, e. g., about 0.05% to about 1% nickel, upto about 1% cobalt, e. g., about 0.01% to about 0.25% cobalt, up toabout 0.5 manganese, e. g., about 0.05% to about 0.5 manganese, lessthan about 1% aluminum, less than about 1% copper, etc.

The agents preferably are devoid of the elements arsenic, antimony, tin,bismuth, selenium, zirconium, titanium, etc., in amounts which aresubversive in the cast iron to the desired effects .of magnesium. Whencerium is present in the agents aforedescr'ibed, the effects of thesesubversive elements are minimized.

For the purpose of giving those skilled in the art a No. Percent PercentPercent Percent Percent Others Mg Ca Fe l2. 5 5. 2 12 70 13. 5 5 26. 854. 5 13. 6 4. 6 12 69. 5 14 5 12 Bal. 14. 7 5 20. 6 Bal. 15 5 12 68 1510 11 64 15 '8 20 Bal. 18. 3 5 11 65 22. 8 5 11 61 27. 6 5 10 57 15 7Bal. 60 0.6 Mischmetal. 12 5 Bal. 55 0.8 Mischrnetal. 17 8 Bel. 65 2Mischmeta-l.

For the purpose of giving those skilled in the art a betterunderstanding of the invention, the following illustrative examples aregiven:

Example 1 Alloy Percent Percent Percent Percent i Mg: Ca

Mg a e Si 1 Ratio 15 5 10 Bal. 3:1 15 10 8 Hal. 1. 5: 1 15 15 6 Bel. 1:1

Percent Percent Mg:0a Ratio Retained Mg Re- Mg covery 1 1 As calculatedfrom the formula given hereinafter.

Example 2 The marked difference in magnesium recovery between Alloy Bhaving a MgzCa ratio of 1.5:1 and Alloy C having a MgzCa ratio of 1:1was confirmed when the experiments outlined in Example 1 were againrepeated using 3% additions of Alloys B and C to treat portions ofmolten cast iron having the same composition as given in Example 1. Theresulting castings were analyzed for magnesium with the followingresults:

Percent Percent MgzOa Ratlo Retained Mg Re- Mg cover-y 1 1 As calculatedfrom the formula given hereinafter.

Example 3 balance essentially silicon. The addition alloy reacted morequietly with, and dissolved more rapidly in, the molten cast iron than acomparable calcium-free addition alloy. The thus-treated metal was thencast without further treatment into a number of castings. The resultingcastings were gray cast iron which contained graphite in a spheroidalform and contained about 0.06% magnesium, about 3.2% carbon, about 1%silicon, about 0.2% manganese and about 0.03% phosphorus. The retainedmagnesium content of 0.06% represents a magnesium recovery, calculatedin the manner set forth hereinafter, of about 26% for this additionalloy. A comparable calcium-free addition alloy would have provided amagnesium recovery of less than 15%. A 1.2-inch diameter sand-castarbitration bar casting made from said metal when tested transverselyover 12-inch centers broke at a load of about 9100 pounds with adeflection of about 0.26 inch while l-inch keel block castings made ofsaid metal had a hardness of about 240 Brinell and exhibited a yieldstrength of about 51,000 pounds and a tensile strength of about 70,000pounds.

Example 4 About 200 pounds of gray cast iron melted in an indirect arcfurnace and containing about 0.12% sulfur, about 3.4% carbon and about1% silicon were ladled upon a 2.5% addition of an alloy similar to thatused in Example 1. This addition alloy reacted quietly and dissolvedrapidly in the melt whereas a comparable calcium-free alloy wasconsiderably more reactive and took a much longer time to dissolve inthe melt. The thus-treated metal was then cast without further treatmentinto a number of castings which had a steely fracture and had amicrostructure containing spheroidal graphite with substantially no freecarbides. The castings contained about 0.074% retained magnesium, about3.4% carbon and about 2.6% silicon. The retained magnesium content ofabout 0.074% represents a magnesium recovery, calculated in the mannerset forth hereinafter, of about 29% for this alloy Whereas a comparablecalcium-free alloy provided a magnesium recoveryv of only 9% undersimilar conditions. A 1.2-inch diameter sand-cast arbitration barcasting made in this manner when tested transversely over 12-inchcenters broke at a load of about 9700 pounds with a deflection of about0.28 inch. One-inch keel bar castings made from said metal had ahardness of about 195 Brinell and exhibited a yield strength of about59,000 pounds per square inch, a tensile strength of about 81,500 poundsper square inch and an elongation of about 13.5%.

Example 5 About 200 pounds of indirect arc furnace melted cast ironsimilar to that described in Example 2 was ladled upon a 2.5% additionof an agent containing about magnesium, about 10% calcium, about 8%iron, with the balance essentially silicon. This addition alloy reactedquietly and dissolved rapidly in the melt whereas a comparablecalcium-free alloy was considerably more reactive and required a muchlonger time to dissolve in the melt. The thus-treated metal was castWithout further treatment into a number of castings which had a .steelyfracture and had a microstructure containing spheroidal graphite withsubstantially no free carbides. The castings contained about 0.064%retained magnesium, about 3.3% carbon and about 2.6% silicon. Thisretained magnesium content represents a magnesium recovery of'about 25%,as calculated in the manner set forth hereinafter, whereas a comparablecalcium-free alloy provided a magnesium recovery of only 9% undersimilar conditions. A 1.2-inch diameter sand-cast arbitration barcasting made in this manner when tested over 12-inch centers broke at aload of about 9200 pounds with a deflection of about 0.2 inch, and1-inch keel bar castings made in this manner exhibited a yield strengthof about 57,000 pounds, a tensile strength Percent Percent. PercentPercent Mg Ca Fe Si 15 15 6 Bal. 15 10 8 Bal. 18 5 10 Bal. 23 5 9 Bal.

Sufficient of these alloys was added to separate portions of cast ironmelts containing about 0.12% sulfur, about 3.5% carbon and about 1%silicon to comprise a magnesium addition of about 0.45% in each case,and the magnesium recovery which was obtained in each case is asfollows:

Ratio MgzCa Mg Recovery 1 1 Percent Mg Rec0very= Percent Retained Mg x(Percent Mg Added)(Percent S in Original Iron) Those skilled in the artwill appreciate that a number of practical operating factors willinfluence the recovery of magnesium in cast .iron when said cast iron istreated with the agents contemplated in accordance with the presentinvention. Thus, the temperature of the molten iron treated is a factor;the sulfur content is a factor since the sulfur content of the bath mustbe reduced to a low value, e. g., less than about 0.02%, before retainedmagnesium becomes effective in controlling graphite in cast iron to thespheroidal form; the manner in which the agent is added to the moltencast iron is a factor; the particle size of the addition agent is afactor; the time the molten bath is held before casting after theaddition of the agent to the iron is a factor; etc. However, for mostpractical purposes, additions of 3% or less of the agent provided inaccordance with the present invention will produce cast iron castingscontaining magnesium in an amount suflicient to control the occurrenceof graphite in said castings in the spheroidal form. For example,additions of 3% or less will generally be suflicient in treating bathsranging in temperature from about 2500 F. to about 2750 F. andcontaining sulfur up to about 0.15%. It has been found that, in treatingamounts of molten iron up to about 300 pounds, the agents and alloyscontemplated in accordance with the present invention preferably aresized in the particle size range of about inch to about 4 inch, sincethis particle size range provides improved magnesium recoveries in theiron castings resulting from the addition of said agents to molten castiron. In treating larger quantities of iron, a larger particle size cansatisfactorily be employed.

As those skilled in the art know, cast iron is essentially an alloy ofiron, carbon and silicon in which the carbon is present in excess of theamount which can be retained in solid solution in austenite at theeutectic temperature. Preferably, the cast iron to be treated with theagents contemplated by the present invention contains at least about 87%iron and is characterized by having iron in the alpha form atatmospheric temperatures. The cast iron preferably contains about 2% to4.5% carbon and about 1.3% to 5% silicon, for example, about 2.5% to 4%carbon and about 1.5% to about 4.5% silicon. Such cast irons may containsmall amounts of alloying elements less i than a total at about 8%, e.g., up to about nickel, up to about 1% molybdenum, up to about 1%chromium, etc. Manganese, sulfur and phosphorus normally are notconsidered alloy additions. Preferably the manganese content of the castiron is less than about 1%. The bath to be treated may contain up to0.25% or even 0.5% phosphorus although it is preferred that thephosphorus content be below about 0.15%, e. g., about 0.02% to 0.06%.Similarly, the sulfur content may be as high as 0.2% or more, e. g.,0.005% to 0.2%, although it is preferred that the sulfur content bebelow 0.15%, e. g., 0.03% to0.l%.

Although magnesium retained in small amounts effective to controlgraphite to a compacted form, including a spheroidal form, .in cast ironwhitening effect therein, the special magnesium-containing agentprovided in accordance with the present invention has an enhancedsimultaneous inoculating effect which tends to compensate for thewhitening effect of the magnesium content on the cast iron treated.Thus, in many instances, no supplemental graphitizing inoculation suchas that provided by a late silicon addition is required in employing theagent provided in accordance with the present invention. For example,magnesium-containing iron castings 1 inch or more in section frequentlyneed not be given a supplemental inoculation to insure graphitization.Similarly, when such as-cast irons contain about 2.25% silicon, castings/2 inch or more in section may be cast carbide-free without supplementalinoculation, and at a silicon content of about 2.75% or more, it-inchcast iron castings may be cast carbide-free without supplemental siliconinoculation. However, even in such cases, supplementary graphitizinginoculation such as a late addition of ferrosilicon will still producedesirable effects, including higher strength, etc., in themagnesiumcontaining iron.

The special magnesium-containing agents contemplated in accordance withthe present invention may be manufactured in alloy form usingconventional melting equipment. For example, in induction furnacemelting, these special alloys may be prepared by melting togethercalcium-silicon, ferrosilicon and magnesium to provide the desiredcomposition. Preferably, half the calcium-silicon (a commercial productcontaining about 30% to about 33% calcium) required to provide thedesired calcium content is charged in the bottom of the furnace followedby the ferrosilicon (a commercial product containing about 50% to about85% silicon) and the remaining calcium-silicon is then charged on top.As soon as the charge is molten, the magnesium should be added. In thismanner, the magnesium may be added at a temperature below its boilingpoint, thereby eliminating magnesium flare and practically eliminatingthe magnesium smoke. Magnesium lowers the melting point of the meltedcalcium-silicon-ferrosilicon mixture sufiiciently that power may beshutoff during the magnesium addition.

The agents may also be prepared in the form of briquettes using powderedingredients such as magnesium powder, ferrosilicon powder,calcium-silicon powder, etc., to give the required composition andemploying a suitable binder to provide solidity in the briquette.

Although the theoretical explanation is not fully understood, it hasbeen established through many tests that calcium in the proper ratio tomagnesium has a very beneficial effect in improving the additioncharacteristics of and in improving the magnesium recovery from theagent of the invention. The effect of calcium in the special amounts andproportions set forth hereinbefore promotes quiet addition behavior andmore rapid solution in the molten cast iron, and markedly reduces theviolence of the addition reactions when molten cast iron is treated withalloys and agents provided by the present invention.

Although the present invention has been described in conjunction withcertain preferred embodiments thereof, those skilled in the art willunderstand that variations has a very powerful and modifications thereofcan be made. Such variations and modifications are to be consideredwithin the purview and scope of the specification and the appendedclaims.

We claim:

1. As a new article of manufacture, an addition agent adapted tointroduce magnesium into cast iron comprising about 12% to about 20%magnesium, about 5% to about 10% calcium, with the ratio of magnesium tocalcium being between about 1.521 and about 3.521, about 8% to about 20%iron, and the balance essentially silicon.

2. As a new article of manufacture, an addition agent adapted tointroduce magnesium into cast iron comprising about 12% to about 20%magnesium, about 5% to about 10% calcium, with the ratio of magnesium tocalcium being between about 1.521 and 35:1 and the ratio of magnesium tosilicon being between about 1:3 and 1:6, about 8% to about 20% iron, andthe balance essentially silicon.

3. As a new article of manufacture, an addition alloy adapted tointroduce magnesium into cast iron comprising about 12% to about 20%magnesium, about 5% to about 10% calcium, with the ratio of magnesium tocalcium being between about 1.521 and about 3.5:1, about 8% to about 20%iron, up to about 2% cerium, and the balance essentially silicon.

4. As a new article of manufacture, an addition agent adapted tointroduce magnesium into cast iron comprising about 10% to about 25%magnesium, about 5% to about 10% calcium, up to about 30% iron, with theratio of magnesium to calcium being between about 1.5 to 1 and about 3.5to 1, and the balance essentially silicon.

5. As a new article of manufacture, an addition agent adapted tointroduce magnesium into cast iron comprising about 10% to about 25magnesium, about 3% to about 14% calcium, up to about 30% iron, with theratio of magnesium to calcium being between about 1.5 to 1 and about 3.5to 1, and the balance essentially silicon.

6. As a new article of manufacture, an addition alloy adapted tointroduce magnesium into cast iron comprising about 10% to about 25%magnesium, about 3% to about 14% calcium, up to about 30% iron, with theratio of magnesium to calcium being between about 1.321 and 5.5 1, andthe balance essentially silicon.

7. As a new article of manufacture, an addition agent adapted tointroduce magnesium into cast iron comprising about 10% to about 25%magnesium, about 3% to about 14% calcium, up to about 5% cerium, up toabout 30% iron, with the ratio of magnesium to calcium being betweenabout 1.3:1 and 5.5:1, and the balance essentially silicon.

8. The process for producing magnesium-containing cast iron whichcomprises establishing a bath of molten cast iron and introducing intosaid bath an effective amount up to about 3% of an agent comprisingabout 12% to about 20% magnesium, about 5% to about 10% calcium andabout 8% to about 20% iron, with the ratio of magnesium to calcium beingbetween about 1.521 and 3.5 :1 and the ratio of magnesium to siliconbeing between about 1:3 and 1:6, and with the balance being essentiallysilicon.

9. The improved process for introducing magnesium into molten cast ironwhich comprises establishing a bath of molten cast iron andincorporating magnesium therein by adding an effective amount up toabout 3% of an alloy containing 12% to about 20% magnesium, about 5% toabout 10% calcium, with the ratio of magnesium to calcium being betweenabout 15:1 and 35:1, up to about 5% cerium, about 8% to about 20% iron,and the balance essentially silicon, and thereafter casting metal fromsaid bath to produce cast iron castings containing magnesium.

10. The process for producing an improved cast iron which comprisesestablishing a bath of molten cast iron, introducing into said bath atleast a small but effective amount of magnesium as an alloy containingabout 10% to about 25% magnesium, about 3% to about 14% calcium, up toabout 30% iron, with the ratio of magnesium to calcium being betweenabout 1.3:1 and 5.511, with the balance essentially silicon, andthereafter casting metal from said bath in an inoculated condition toproduce castings containing a small but effective amount of magnesiumand containing graphite in a compacted form.

11. The process for producing an improved cast iron which comprisesestablishing a bath of molten cast iron, introducing into said bath atleast a small but effective amount of magnesium as an agent containingabout 10% to about 25% magnesium, about 3% to about 14% calcium, up toabout 30% iron, up to about 5% cerium, with the ratio of magnesium tocalcium being between about 7 1.321 and 5.5:1, with the balanceessentially silicon, and

thereafter casting metal from said bath in an inoculated condition toproduce castings containing a small but eifective amount of magnesiumand containing graphite in a compacted form.

12. As a new article of manufacture, an addition alloy adapted tointroduce magnesium into cast iron comprising about 10% to about 30%magnesium, about 3% to about 14% calcium, up to .about 30% iron, withthe ratio of magnesium to calcium being between about 1.3 to 1 and about5.5 to 1, and the balance essentially silicon.

13. The process [for producing an improved cast iron The AmericanFoundryman,

which comprises establishing a bath of molten cast iron, introducinginto said bath at least a small but effective amount of magnesium as analloy containing about 10% to about magnesium, about 3% to about 14%calcium, up to about 30% iron, with the ratio of magnesium to calciumbeing between about 1.3 to 1 and about 5 .5 to 1, and the balanceessentially silicon, and thereafter casting metal from said bath in aninoculated condition to produce casting containing a small but effectiveamount of magnesium and containing graphite in a compacted form.

14. An addition agent according to claim 12 wherein cerium isincorporated in an amount up to about 5%.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES February 1951, pages 42 and 43.

1. AS A NEW ARTICLE OF MANUFACTURE, AN ADDITION AGENT ADAPTED TOINTRODUCE MAGNESIUM INTO CAST IRON COMPRISING ABOUT 12% TO ABOUT 20%MAGNESIUM, ABOUT 5% TO ABOUT 10% CALCIUM, WITH THE RATIO OF MAGNESIUM TOCALCIUM BEING BETWEEN ABOUT 1.5:1 AND ABOUT 3.5:1, ABOUT 8% TO ABOUT 20%IRON, AND THE BALANCE ESSENTIALLY SILICON.